U.S. patent application number 12/702502 was filed with the patent office on 2011-04-21 for inflatable minimally invasive system for delivering and securing an annular implant.
This patent application is currently assigned to ST. JUDE MEDICAL. Invention is credited to James Badia, Luis Baez, Peter Bentley, John P. Cartledge, Richard G. Cartledge, James McCrea.
Application Number | 20110093062 12/702502 |
Document ID | / |
Family ID | 42542682 |
Filed Date | 2011-04-21 |
United States Patent
Application |
20110093062 |
Kind Code |
A1 |
Cartledge; Richard G. ; et
al. |
April 21, 2011 |
INFLATABLE MINIMALLY INVASIVE SYSTEM FOR DELIVERING AND SECURING AN
ANNULAR IMPLANT
Abstract
A delivery device for an annular implant that includes a balloon
expansion mechanism and an annular implant having an adjustable
dimension. The balloon expansion mechanism includes an inflation
tube attached to a non-occluding balloon collar which is supported
by trusses radially extending from a trocar. The annular implant
further includes a flexible ring core, contiguous coiled spacers,
and anchoring blocks. The flexible ring core is adjusted via a
cinching mechanism. The anchoring blocks are spaced along the ring
core by the contiguous coiled spacers, which keeps the distance
between each pair of anchoring blocks equidistant as the ring core
diameter is manipulated by the device user. The annular implant can
also include gunbarrel elements housed in the trocar. Each
gunbarrel element contains a gunbarrel pusher which drives an
attachment element into the annular implant and annular tissue.
Inventors: |
Cartledge; Richard G.; (Boca
Raton, FL) ; Cartledge; John P.; (Boca Raton, FL)
; Badia; James; (Redwood City, CA) ; McCrea;
James; (Burlingame, CA) ; Baez; Luis;
(Mountain View, CA) ; Bentley; Peter; (San Jose,
CA) |
Assignee: |
ST. JUDE MEDICAL
|
Family ID: |
42542682 |
Appl. No.: |
12/702502 |
Filed: |
February 9, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61151061 |
Feb 9, 2009 |
|
|
|
Current U.S.
Class: |
623/2.11 |
Current CPC
Class: |
A61F 2/2466 20130101;
A61F 2220/0016 20130101; A61F 2250/0059 20130101; A61B 2017/00243
20130101; A61F 2250/001 20130101; A61F 2/2439 20130101; A61F 2/2445
20130101; A61B 17/0644 20130101; A61F 2002/30537 20130101; A61B
2017/0414 20130101; A61F 2/0031 20130101; A61B 17/0401 20130101;
A61F 2/2433 20130101; A61B 17/064 20130101; A61B 2017/0647
20130101; A61F 2250/0004 20130101; A61B 17/0487 20130101; A61B
2017/0496 20130101; A61B 2017/0649 20130101; A61M 2025/1097
20130101 |
Class at
Publication: |
623/2.11 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1. A delivery device for an annular implant comprising: a balloon
expansion mechanism, wherein the balloon expansion mechanism
comprises a hollow catheter attached to an inflation tube whereby a
gas or liquid is fed through said inflation tube and a
non-occluding balloon collar attached to the inflation tube to
provide for expansion of the balloon collar, wherein the balloon
collar is supported by a plurality of trusses radially extending
from a trocar; and an annular implant having an adjustable
dimension removably mounted around the non-occluding balloon
collar.
2. The delivery device of claim 1, wherein the balloon collar is
either cylindrical or spherical in shape.
3. The delivery device of claim 1, wherein the balloon collar is
any size or shape suitable for deployment in a lumen.
4. The delivery device of claim 1, wherein the balloon is made of a
flexible biocompatible material.
5. The delivery device of claim 1, wherein a check valve is
incorporated into the balloon expansion mechanism.
6. The delivery device of claim 1: wherein the annular implant
comprises a flexible ring core and wherein the flexible ring core
is adjustable through two cinching cords; and further comprising a
cinching mechanism attached to the flexible ring core, wherein said
cinching mechanism reshapes the annular implant to conform to the
size and shape of the annulus via the cinching cords.
7. The delivery device of claim 1, further comprising: a plurality
of gunbarrel elements, wherein each gunbarrel element contains a
hollow insert and a gunbarrel pusher and wherein the gunbarrel
pusher drives an attachment element into the annular implant and
annular tissue; a plurality of anchoring blocks attached to the
annular implant, wherein each gunbarrel element is anchored into a
corresponding anchoring block; a plurality of contiguous coiled
spacers coiled along the annular implant, wherein each coiled
spacer keeps each pair of anchoring blocks equidistant as the
annular implant diameter is manipulated; a trocar releasably
housing the gunbarrel elements; and a proximal control interface
having control mechanisms for inflation of the balloon collar and
deployment of the attachment elements.
8. The delivery device of claim 7, wherein the trocar houses an
alignment disc, wherein the alignment disc provides separation to
the gunbarrel elements during device introduction.
9. The delivery device of claim 6, wherein the cinching mechanism
comprises: a trap element inside a hollow cylindrical housing; and
a pushrod adjacent to the trap element, wherein said pushrod
engages the trap element to control movement of the cinching cords,
thereby controlling the adjustment of the flexible ring core.
10. The delivery device of claim 6, wherein the cinching mechanism
comprises a ratchet mechanism.
11. The delivery device of claim 6, wherein the cinching mechanism
comprises a wedge-pin mechanism.
12. The delivery device of claim 6, wherein the cinching mechanism
comprises a cam structure.
13. The delivery device of claim 6, wherein the annular implant has
an upper compartment housing said flexible ring core and a lower
compartment containing a series of retention barbs either
integrally formed with or fixedly attached to the annular implant,
wherein selected retention barbs further contain a terminal hook
for firm anchoring of the annular implant into the annular tissue;
and a movable retainer guide in communication with the lower
compartment of the annular implant controls extension of the series
of retention barbs.
14. The delivery device of claim 13, wherein said lower compartment
contains a retention barb housing which prevents the retention barb
from engaging the valve annulus prior to deployment.
15. The delivery device of claim 13 wherein the exterior of the
annular implant is fabricated of a biologically compatible material
such as Dacron, PTFE, malleable metals, other biologically
compatible materials, or a combination of such biologically
compatible materials in a molded, woven, or non-woven
configuration.
16. The delivery device of claim 7, wherein said control interface
comprises: a plurality of attachment activator buttons, wherein
each attachment activator button has the capacity to drive a single
attachment element and hollow insert into the annular implant and
valve annulus; and a two-button activation device wherein said
two-button activation device attaches to each attachment activator
button individually, which allows the device user to control
delivery of the hollow insert and the attachment element into the
annular implant and valve annulus.
17. A reversible attachment apparatus comprising: an annular
implant having an upper compartment housing said flexible ring core
and a lower compartment containing a series of retention barbs
either integrally formed with or fixedly attached to the annular
implant, wherein selected retention barbs further contain a
terminal hook for firm anchoring of the annular implant into the
annular tissue; and a movable retainer guide in communication with
the lower compartment of the annular implant controls extension of
the series of retention barbs.
18. The reversible attachment apparatus of claim 17, wherein said
lower compartment contains a retention barb housing which prevents
the retention barb from engaging the valve annulus prior to
deployment.
19. The reversible attachment apparatus of claim 17, wherein the
lower compartment comprises foam or a foam-like material through
which the retention barbs extend to contact the annulus when
deployed by the retaining guide.
20. The reversible attachment apparatus of claim 17, wherein the
exterior of the annular implant is fabricated of a biologically
compatible material such as Dacron, PTFE, malleable metals, other
biologically compatible materials, or a combination of such
biologically compatible materials in a molded, woven, or non-woven
configuration.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The application claims priority to U.S. Provisional
Application No. 61/151,061, filed Feb. 9, 2009, which application
is expressly incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the delivery of
an implantable device, and more particularly to methods and devices
for delivering and securing an annular implant to control the
internal circumference of an annulus.
BACKGROUND OF THE INVENTION
[0003] Many anatomic structures in the mammalian body are hollow
passages in which walls of tissue define an annulus, which serves
as a conduit for blood, other physiologic fluids, nutrient matter,
or waste matter passing within the structure. In many physiologic
settings, dysfunction may result from a structural annulus which is
either too large or too small. In most such cases, dysfunction can
be relieved by interventional changes in the size of the
annulus.
[0004] Thus in surgery, there is often a need to reduce the
internal circumference of an annulus or other open anatomic
structure to narrow the size of the annulus or opening to achieve a
desired physiologic effect. Often, such surgical procedures require
interruption in the normal physiologic flow of blood, other
physiologic fluids, or other structural contents through the
annulus or structure. The exact amount of the narrowing required
for the desired effect often cannot be fully appreciated until
physiologic flow through the annulus or structure is resumed. It
would be advantageous, therefore, to have an adjustable means of
achieving this narrowing effect, such that the degree of narrowing
could be changed not only after its implantation, but after the
resumption of normal physiologic flow in situ.
[0005] One example of a dysfunction within an anatomic lumen is in
the area of cardiac surgery, and specifically valvular repair.
Approximately one million open heart surgical procedures are now
performed annually in the United States, and twenty percent of
these operations are related to cardiac valves.
[0006] The field of cardiac surgery was previously transformed by
the introduction of the pump oxygenator, which allowed open heart
surgery to be performed. Valvular heart surgery was made possible
by the further introduction of the mechanical ball-valve
prosthesis, and many modifications and different forms of
prosthetic heart valves have since been developed. However, the
ideal prosthetic valve has yet to be designed, which attests to the
elegant form and function of the native heart valve. As a result of
the difficulties in engineering a perfect prosthetic heart valve,
there has been growing interest in repairing a patient's native
valve. These efforts have documented equal long-term durability to
the use of mechanical prostheses, with added benefits of better
ventricular performance due to preservation of the subvalvular
mechanism and obviation of the need for chronic anticoagulation.
Mitral valve repair has become one of the most rapidly growing
areas in adult cardiac surgery today.
[0007] Mitral valve disease can be subdivided into intrinsic valve
disturbances and pathology extrinsic to the mitral valve ultimately
affecting valvular function. Although these subdivisions exist,
many of the repair techniques for and overall operative approaches
to the various pathologies are similar.
[0008] Historically, most valvular pathology was secondary to
rheumatic heart disease, a result of a streptococcal infection,
most commonly affecting the mitral valve, followed by the aortic
valve, and least often the pulmonic valve. The results of the
infectious process are mitral stenosis and aortic stenosis,
followed by mitral insufficiency and aortic insufficiency. With the
advent of better antibiotic therapies, the incidence of rheumatic
heart disease is on the decline, and accounts for a smaller
percentage of valvular heart conditions in the developed world of
the present day. Commissurotomy of rheumatic mitral stenosis was an
early example of commonly practiced mitral valve repair outside of
the realm of congenital heart defects. However, the repairs of
rheumatic insufficient valves have not met with good results due to
the underlying valve pathology and the progression of the
disease.
[0009] Most mitral valve disease other than rheumatic results in
valvular insufficiency that is generally amenable to repair.
Chordae rupture is a common cause of mitral insufficiency,
resulting in a focal area of regurgitation. Classically, one of the
first successful and accepted surgical repairs was for ruptured
chordae of the posterior mitral leaflet. The technical feasibility
of this repair, its reproducible good results, and its long-term
durability led the pioneer surgeons in the field of mitral valve
repair to attempt repairs of other valve pathologies.
[0010] Mitral valve prolapse is a fairly common condition that
leads over time to valvular insufficiency. In this disease, the
plane of coaptation of the anterior and posterior leaflets is
"atrialized" relative to a normal valve. This problem may readily
be repaired by restoring the plane of coaptation into the
ventricle.
[0011] The papillary muscles within the left ventricle support the
mitral valve and aid in its function. Papillary muscle dysfunction,
whether due to infraction or ischemia from coronary artery disease,
often leads to mitral insufficiency (commonly referred to as
ischemic mitral insufficiency). Within the scope of mitral valve
disease, this is the most rapidly growing area for valve repair.
Historically, only patients with severe mitral insufficiency had
their mitral valve repaired or replaced, but there is increasing
support in the surgical literature to support valve repair in
patients with moderate insufficiency that is attributable to
ischemic mitral insufficiency. Early aggressive valve repair in
this patient population has been shown to increase survival and
improve long-term ventricular function.
[0012] In addition, in patients with dilated cardiomyopathy the
etiology of mitral insufficiency is the lack of coaptation of the
valve leaflets from a dilated ventricle. The resultant
regurgitation is due to lack of coaptation of the leaflets. There
is a growing trend to repair these valves, thereby repairing the
insufficiency and restoring ventricular geometry, and thus
improving overall ventricular function.
[0013] The two essential features of mitral valve repair are to fix
primary valvular pathology (if present) and to support the annulus
or reduce the annular dimension using an implantable device that is
commonly in the form of a ring or band. The problem encountered in
mitral valve repair is the surgeon's inability to fully assess the
effectiveness of the repair until the heart has been fully closed,
and the patient is weaned off cardiopulmonary bypass. Once this has
been achieved, valvular function can be assessed in the operating
room using transesophageal echocardiography (TEE). If significant
residual valvular insufficiency is then documented, the surgeon
must re-arrest the heart, re-open the heart, and then repair or
replace the valve. This increases overall operative, anesthesia,
and bypass times, and therefore increases the overall operative
risks.
[0014] If the implant used to reduce the annulus is larger than the
ideal size, mitral insufficiency may persist. If the implant is too
small, mitral stenosis may result. The need exists, therefore, for
an adjustable implant that would allow a surgeon to adjust the
annular dimension in situ in a beating heart under the guidance of
TEE or another diagnostic modality to achieve optimal valvular
sufficiency and function.
[0015] Cardiac surgery is but one example of a setting in which
adjustment of the annular dimension of an anatomic orifice in situ
would be desirable. Another example is in the field of
gastrointestinal surgery, where the Nissen fundoplication procedure
has long been used to narrow the gastro-esophageal junction for
relief of gastric reflux into the esophagus. In this setting, a
surgeon is conventionally faced with the tension between creating
sufficient narrowing to achieve reflux control, and avoiding
excessive narrowing that may interfere with the passage of nutrient
contents from the esophagus into the stomach. "Gas bloat," which
causes the inability to belch, is also a common complication of
over-narrowing of the gastro-esophageal junction. Again, it would
be desirable to have a method and apparatus by which the extent to
which the gastro-esophageal junction is narrowed could be adjusted
in situ to achieve optimal balance between those two competing
interests.
[0016] Another example of a surgical procedure in need of
improvement for narrowing an anatomic space is that for gastric
bypass used in obesity control. In such a procedure, the goal is to
reduce the available stomach volume adjacent to the esophagus in
order to earlier stimulate satiation signaling with less food
consumption. Prior art technologies include externally suturing or
stapling a line of opposing stomach walls together to form a pouch
in the upper stomach. This surgical strategy has the disadvantage
of requiring invasive surgery to access the exterior of the
stomach, and both sides thereof in the case of stapling with a
required anvil, in addition to the lack of post operative
adjustability of the pouch size. Alternative prior art gastric
bypass attempts include encircling the stomach with an inflatable
lap band, or Angel Chick prosthesis ring, to compress the stomach
into smaller compartments. These techniques are disadvantageous
again due to the surgically invasive procedure for applying the
bands externally to the stomach, in addition to the high incidence
of necrosis as the result of constricting the tissues.
[0017] Aside from the problem of adjusting the internal
circumference of body passages in situ, there is often a need in
medicine and surgery to place an implantable device at a desired
recipient anatomic site. For example, existing methods proposed for
percutaneous mitral repair include approaches through either the
coronary sinus or percutaneous attempts to affix the anterior
mitral leaflet to the posterior mitral leaflet. Significant
clinical and logistical problems attend both of these existing
technologies. In the case of the coronary sinus procedures,
percutaneous access to the coronary sinus is technically difficult
and time consuming to achieve, with procedures which may require
several hours to properly access the coronary sinus. Moreover, many
of these procedures employ incomplete annular rings, which
compromise their physiologic effect. Moreover, the coronary sinus
approach does not address the correction of diseased annular
tissues, particularly on the posterior annulus of the mitral valve.
Such procedures are typically not effective for improving mitral
regurgitation by more than one clinical grade. Finally, coronary
sinus procedures carry the potentially disastrous risks of either
fatal tears or catastrophic thrombosis of the coronary sinus.
[0018] Similarly, percutaneous procedures which employ sutures,
clips, or other devices to affix the anterior mitral leaflets to
the posterior mitral leaflets also have limited reparative
capabilities. Such procedures are also typically ineffective in
providing a complete repair of mitral regurgitation. These
procedures also fail to address the pathophysiology of the dilated
mitral annulus in ischemic heart disease. As a result of the
residual anatomic pathology, no annular repair, ventricular
remodeling or improved ventricular function is likely with these
procedures.
[0019] The need exists, therefore, for a delivery system and
methods for its use that would avoid the need for open surgery in
such exemplary circumstances, and allow delivery, placement, and
adjustment of a prosthetic implant to reduce the diameter of a such
an annulus in a percutaneous or other minimally invasive procedure,
while still achieving clinical and physiologic results that are at
least the equivalent of the yields of the best open surgical
procedures for these same problems. Further, the need exists for a
system that allows remote attachment of such an implant to the
desired anatomic recipient site in a percutaneous or other
minimally invasive procedure.
[0020] The need exists for implant delivery systems and methods
which permit improved certainty of correct placement location
thereof by visual and/or physical sensations of the operator. There
exists a need for improved delivery systems which permit reshaping
of the annular tissue to match the delivery configuration of the
implant and insure consistent contact therewith for proper
attachment. Furthermore, there exists a need to provide a minimally
invasive delivery system for attaching an implant to adjacent
tissues without manual placement of sutures or staples requiring
opposing forces against the target tissues.
[0021] As mentioned, the preceding cardiac applications are only
examples in which such a delivery system is desirable. Another
exemplary application is in the field of gastrointestinal surgery,
where the aforementioned Nissen fundoplication procedure has long
been used to narrow the gastro-esophageal junction for relief of
gastric reflux into the esophagus. Gastric bypass surgery for
treatment of moribund obesity is another field in need of
improvement. There are many other potential applications in the
broad fields of medicine and surgery. Among the other potential
applications anticipated are adjustable implants for use in the
treatment of urinary incontinence, anastomotic strictures, arterial
stenosis, cervical incompetence, ductal strictures, and anal
incontinence.
SUMMARY OF THE INVENTION
[0022] Devices and methods for delivering and securing an annular
implant to control the internal circumference or shape of an
annulus are provided by the present invention. The invention also
provides devices and methods which permit improved certainty of
preferred tissue placement location thereof by providing visual
and/or physical information to the operator. The invention provides
devices and methods which provide a minimally invasive delivery
system for attaching an implant to adjacent tissues without
sutures. These and many other advantages and features of the
invention will become apparent to those skilled in the art upon
reading the present specification of the preferred embodiments.
[0023] In one aspect, the device of the present invention provides
a delivery device for an annular implant that includes a
non-occluding inflatable balloon, a balloon expansion mechanism and
an annular implant disposed thereon having an adjustable dimension.
The balloon expansion mechanism includes an inflation tube attached
to a non-occluding balloon collar which is supported by a plurality
of trusses radially extending from a trocar. The annular implant
has an adjustable dimension removably mounted around the
non-occluding balloon collar. The non-occluding balloon collar is
deliberately hollow, or tubular, so that blood may continue to flow
through the annulus when the balloon is inflated.
[0024] The balloon collar can be inserted into the annulus in need
of repair in its deflated position and then inflated.
Alternatively, the balloon collar may be pre-inflated to its
partially or fully expanded shape outside of the valve annulus,
then advanced down through the annulus.
[0025] The annular implant may be positioned around the balloon
collar so that its expansion and contraction is controlled by the
expansion and contraction of the balloon. Alternatively, the
annular implant may be independently introduced after the balloon
collar is appropriately positioned in the annulus and delivered
using the shape of the inflated balloon. Visual confirmation of the
proper placement of the annular implant can be confirmed, such as
with echocardiography or fluoroscopy, and radiopaque markings on
the device.
[0026] In a preferred embodiment where the annulus includes an
anatomical valve, such as a mitral valve, a mechanical check valve
is incorporated into the delivery device. The check valve
temporarily replaces the function of the biological valve, during
the time that the balloon collar is distended and the biological
valve is held open and non-functional. The check valve can be a
monoleaflet, bileaflet, or ball/cage design, similar to mitral
valve prosthetic devices known in the art.
[0027] In another preferred aspect, a device is provided for
delivering and securing a flexible annular implant comprising a
flexible ring core, contiguous coiled spacers, and anchoring
blocks. The ring core and coiled spacers can be encased in a
protective sheath. The anchoring blocks are spaced along the ring
core by the contiguous coiled spacers, which keep a predetermined
distance between each pair of anchoring blocks as the ring core
diameter is manipulated by the device user. The anchoring blocks
are attached to the ends of gunbarrel elements that extend from the
tip of the delivery trocar during device operation. These gunbarrel
elements house attachment elements for the implant, as described
below, and can be pre-formed so as to flare radially outward as
they extend from the tip of the trocar.
[0028] In a preferred embodiment, the ring core runs around the
circumference of the device, then through a cinching mechanism. As
the two ends of the ring core pass through the cinching mechanism,
they become cinching cords, which pass up through the trocar of the
device. The flared gunbarrel elements and the cinching cords allow
the user to control the size of the ring core. The flared gunbarrel
elements tend to expand the ring core diameter, whereas the
cinching mechanism allows the user to reduce the ring core diameter
or shape. The device user pulls on the exposed ends of the cinching
cords located at the distal end of the trocar to reduce the
diameter of the ring core. When the device user releases tension on
the cinching cords, a locking mechanism prevents the ring core from
relaxing and the ring diameter from consequently expanding, unless
desired. Through a combination of extension of the gunbarrel
elements from the trocar and tension exerted on the cinching cords,
the device user can tailor the size and shape of the ring core. The
locking mechanism may feature a means by which the user can release
the lock, so that the ring may be readjusted as many times as
necessary to achieve the desired result.
[0029] In certain embodiments, each gunbarrel element is secured
into an anchoring block on the ring core. The gunbarrel elements
are pre-shaped to expand the ring outwards, once the gunbarrel
elements are pushed clear of the trocar. Each gunbarrel element
contains a gunbarrel pusher and a hollow insert, both of which are
activated by the device user via the control interface located
outside of the patient's body. Once the device user determines that
the ring core is positioned correctly upon the annulus, the device
user activates each gunbarrel pusher, which drives an attachment
element into the annular implant and the annular tissue.
[0030] After each attachment element has been deployed, the annular
implant is securely attached to the annulus. A variety of
modalities for assessing mitral function, such as real time trans
esophageal echocardiography, intravascular echocardiography or
fluoroscopy, and intracardiac echocardiography, may be used to
assess the physiologic effect of the implant on the mitral
function. Further adjustments of the device can alter the position,
size and shape of the annular implant. Once a desired result has
been achieved, the annular implant delivery device is
retracted.
[0031] In another embodiment, a device is provided for anchoring
and/or adjusting the annular implant. In this embodiment, a series
of retention barbs may be integrally formed with or fixedly
attached to the interior of the annular implant and are oriented to
facilitate placement, retention, and removal of the annular
implant.
[0032] The exemplary embodiment of this reversible attachment
apparatus employs unidirectional retention barbs. The retention
barbs are oriented in a consistent, tangential position with
respect to the annular implant. The retention barbs may be further
provided with a terminal hook, which allows for firm anchoring of
the annular implant into the surrounding valve annulus. The
retention barb/terminal hook apparatuses are movable between
extended and retracted positions. A movable retainer guide located
adjacent to the annular implant controls the action of the
retention barbs, such as via a worm gear. In the retracted
position, the retention barb/terminal hook apparatuses do not
engage the valve annulus. When the movable retainer guide is
engaged, the retention barb/terminal hook apparatuses extend
through the annular implant and into the valve annulus. The
terminal hooks act like anchors to fix the annular implant to the
valve annulus.
[0033] Other systems, devices, methods, features and advantages of
the disclosed delivery device for an annular implant will be
apparent or will become apparent to one with skill in the art upon
examination of the following figures and detailed description. All
such additional systems, devices, methods, features and advantages
are intended to be included within the description and are intended
to be protected by the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The objects and advantages of the present invention will be
better understood and more readily apparent when considered in
conjunction with the following detailed description and
accompanying drawings which illustrate, by way of example, a
preferred embodiment and in which:
[0035] FIGS. 1A-C are a series of schematic views of the annular
implant delivery device. FIG. 1A is a schematic view showing the
insertion of the annular implant delivery device into and through
the mitral annulus, with the gunbarrels deployed and the balloon
collar deflated. FIG. 1B is a schematic view showing the insertion
of the annular implant delivery device into and through the mitral
annulus, with the gunbarrels deployed and the balloon collar
expanded. FIGS. 1A-1B illustrate the delivery technique by which
the balloon is positioned and expanded in the mitral annulus before
the ring is delivered. FIG. 1C is a schematic view showing the ring
positioned about a pre-inflated balloon and illustrates the
delivery technique by which the ring and balloon are inserted
simultaneously into the mitral annulus.
[0036] FIG. 2 is a schematic view of a patient in the supine
position preparing for implantation of an annular device.
[0037] FIGS. 3A-E are a series of schematic views showing the
non-occluding balloon element of the annular implant delivery
device of FIG. 1. FIG. 3A is a three-dimensional view of the
balloon expansion mechanism, with the balloon collar deflated. FIG.
3B is an end-on view of the balloon expansion mechanism, with the
balloon collar deflated. FIG. 3C is a three-dimensional view of the
balloon expansion mechanism, with the balloon collar inflated. FIG.
3D is a proximal-distal view of the balloon expansion mechanism.
FIG. 3E is another proximal-distal view of the balloon expansion
mechanism.
[0038] FIGS. 4A-D are a series of schematic views showing the
flexible annular implant composed of a flexible ring core,
contiguous coiled spacers, and anchoring blocks, appropriately
positioned by gunbarrel elements. FIG. 4A shows the inside of the
flexible annular implant. FIG. 4B shows the side view of the
flexible annular implant. FIG. 4C shows the proximal-distal view of
the flexible annular implant. FIG. 4D shows the close-up view of
the gunbarrels and block assembly of the flexible annular implant.
FIG. 4E shows a close-up view of a gun barrel and black assembly,
whole and in cross-section.
[0039] FIG. 5A-H are perspective views of various embodiments of
the attachment elements.
[0040] FIGS. 6A-E are a series of views showing various embodiments
of the cinching mechanism depicted in 4A-C. FIG. 6A shows a
beartrap cinch for locking the flexible ring core in place during
adjustment. FIG. 6B shows a ratchet mechanism for locking the
flexible ring core in place during adjustment. FIG. 6C shows a
wedge-pin cinch for locking the flexible ring core in place during
adjustment. FIG. 6D is a cross-section view of the wedge-pin cinch
of FIG. 6C. FIG. 6E shows a simple cam system for locking the
flexible ring core in place during adjustment.
[0041] FIGS. 7A-G are a series of views showing the reversible
attachment apparatus element of the annular implant. FIG. 7A shows
the side-view of the flexible annular implant containing the
reversible attachment apparatus. FIG. 7B depicts one retention
barb/terminal hook apparatus housed inside the lower compartment of
the annular implant. FIG. 7C shows a side-view of the flexible
annular implant containing the reversible attachment apparatus,
whereby the retention barb/terminal hook apparatuses are in a
retracted position. FIG. 7D shows a side-view of the flexible
annular implant containing the reversible attachment apparatus,
whereby the retention barb/terminal hook apparatuses are in an
extended position. FIGS. 7E-G illustrate the variable modes of the
reversible attachment apparatus of the annular implant. FIG. 7E
depicts the compressed mode, whereby the device is in position to
be inserted into the catheter. FIG. 7F depicts post-injection mode,
whereby the annular implant rests passively on top of the valve
annulus. FIG. 7G depicts the activated mode, whereby the annular
implant is attached to the valve annulus via the retention
barb/terminal hook apparatuses.
[0042] FIGS. 8A-D are a series of views showing the control
interface of the annular implant delivery device. FIG. 8A is an
over-head view of the control interface. FIG. 8B is a perspective
of the control interface. FIG. 8C is a perspective view of the
control interface, trochar and annular implant. FIG. 8D is a
side-view of the control interface.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] As required, detailed embodiments of the present invention
are disclosed herein: however, it is to be understood that the
disclosed embodiments are merely exemplary of the invention which
may be embodied in various forms. Therefore, specific structural
and functional details disclosed herein are not to be interpreted
as limiting, but merely as a basis for the claims and as a
representative basis for teaching one skilled in the art to
variously employ the present invention in virtually any
appropriately detailed structure.
[0044] An improved annular implant delivery device has been
developed for use in delivering an annular implant to an annulus in
a patient's body. The delivery device can be housed in an
endoscopic sheath or trocar or other covering, which is inserted
into a patient to deliver an annular implant to an annulus in a
minimally invasive procedure. The delivery procedure can be
performed endoscopically, percutaneously, or with an endoscope
placed within a body cavity or organ, or by trans-abdominal or
trans-thoracic approaches. Thus, advantageously, the delivery
device can help eliminate the need for an invasive surgical
procedure. The delivery device can thereby help reduce the
anesthesia and operative times required for a delivery procedure,
as well as the risk associated with such a procedure, and the
patient pain and recovery time following a procedure.
[0045] Devices and methods for delivering and securing an annular
implant to control the internal circumference or shape of an
annulus are provided by the present invention. The invention also
provides devices and methods which permit improved certainty of
tissue placement of the implant by providing visual and/or physical
information to the operator. The invention provides devices and
methods which remove unintended tissues from the site of
implantation attachment during delivery. The invention provides
devices and methods which permit reshaping of the annular tissue to
match the delivery configuration of the implant and insure more
consistent contact therewith for proper attachment to the implant.
Furthermore, the invention provides devices and methods which
provide a minimally invasive delivery system for attaching an
implant to adjacent tissues without sutures requiring additional
remote manual access or staples requiring opposing forces against
the target tissues.
[0046] Therefore, the delivery device advantageously provides a
means for pushing anatomical structures, such as mitral valves, out
of the path of the device as it approaches the annulus, to help
avoid damage to tissue around the annulus.
[0047] The device also advantageously provides a means of
redesigning the size and shape of an annulus during implantation.
The delivery device provides a structure for forcing the annulus to
conform to the shape and size of the annular implant before
securing the implant to the tissue, thereby creating a precise fit.
The device further provides a structure for adjusting and
maintaining the size and shape of the annulus as desired after the
procedure to achieve a desired physiologic effect.
[0048] The delivery device also advantageously provides a means of
incrementally adjusting the shape or circumference of the annular
implant during a beating-heart or "off-pump" procedure, as well as
after the procedure once the normal physiologic flow has resumed in
situ. The delivery device thereby allows the shape or circumference
of the annulus to be affected until the desired physiologic effect
has been achieved. Further, the circumference or shape of the
annular implant can be adjusted post-operatively, preferably
percutaneously, to accommodate changes in the size, shape, or
physiologic needs of the annulus.
[0049] In various embodiments, the delivery device may be employed
to deliver an implant to internally adjustably constrict or expand
the circumference or other dimensions of an annulus in which a
disease process tends to enlarge such circumference or other
dimensions. In additional various embodiments, the delivery device
may be employed to deliver an implant to adjustably enlarge or
maintain the circumference or other dimensions of an annulus in
which a disease process tends to narrow or constrict such
circumference or other dimensions. As used herein, "annulus"
includes any substantially ring-like valve, sphincter, lumen,
orifice, or other opening in the body. By way of illustration and
not by way of limitation, recipient sites include a heart valve,
blood vessels, the esophagus near the gastro-esophageal junction,
the stomach, the anus, and the cervix.
[0050] In one aspect, the device of the present invention provides
an annular implant having an adjustable dimension, such as the
circumference of the annular implant. One embodiment of the
delivery device of the present invention provides a balloon
expansion mechanism whereby the annular implant is attached to a
non-occluding balloon collar and delivered to the valve annulus via
a catheter. The balloon expansion mechanism is similar to other
balloon dilation catheters in the prior art, as disclosed in U.S.
Pat. No. 6,872,223, U.S. Pat. No. 6,619,291, U.S. Pat. No.
6,217,610, and U.S. Pat. No. 6,168,614.
[0051] The balloon collar can be inserted in its deflated position
and then inflated within the valve annulus to expand and deploy the
annular implant, which can then be secured to the annulus with an
attachment means or anchoring barbs. Alternatively, the balloon
collar can be inserted in the valve annulus in a pre-determined
inflated position. Once the balloon collar in its pre-determined
inflated position is correctly positioned within the valve annulus,
the annular implant can be deployed. Visual confirmation of the
proper placement of the annular implant can be confirmed, such as
with TEE.
[0052] In a preferred embodiment, the balloon expansion mechanism
comprises a hollow catheter attached to an inflation tube whereby a
gas or liquid is fed through said inflation tube and a
non-occluding balloon collar is attached to the inflation tube to
provide for expansion of the balloon collar. The balloon collar is
supported by a plurality of wheel-shaped trusses extending from the
catheter radially support the balloon collar. The balloon collar is
deliberately hollow, or tubular, so that blood may continue to flow
through the annulus when the balloon is inflated.
[0053] In a preferred embodiment, a check valve is incorporated
into the balloon expansion mechanism. The check valve temporarily
replaces the function of the mitral valve, during the time that the
balloon collar is distended and the mitral valve open and
non-functional. The check valve could be a monoleaflet, bileaflet,
or ball/cage design, similar to mitral valve prosthetic devices
known in the art.
[0054] Once the annular implant is properly positioned in the
annulus, the balloon collar is deflated and removed. Such an
operation may include elongating the balloon in the distal
direction and reducing its radial dimension, for example, twisting.
During the retraction of the balloon collar, care must be taken so
as not to damage the valve leaflets.
[0055] The balloon expansion mechanism design offers some
advantages over the "armed" annular expansion mechanisms. First,
the balloon expansion mechanism can be operated with hydraulic
pressure, which eliminates many of the geometrical versus load
issues associated with the arm designs, in addition to making the
design more amenable to a tortuous anatomy and percutaneous
application. Second, the balloon has a generally soft surface as
compared to the "armed" mechanisms, which should minimize trauma to
the annulus when it is activated. Third, the balloon expansion
mechanism pushes the entire annulus apart in one action, as opposed
to the "armed" designs which may require a repeat of the expansion
action followed by a rotation to find new anchoring points. Fourth,
the distal end of the balloon design does not get entangled in any
of the subvalvular apparatus.
[0056] In a preferred embodiment, a device is provided for
delivering and securing a flexible annular implant composed of a
flexible ring core, contiguous coiled spacers, and anchoring
blocks. The anchoring blocks are spaced along the ring core by the
contiguous coiled spacers, which keeps the distance between each
pair of anchoring blocks equidistant as the ring core diameter is
manipulated by the device user. The result of this design would be
a ring that adjusts symmetrically about its entire circumference.
The ring core runs around the circumference of the device, then
through a cinching mechanism. As the two ends of the ring core pass
through the cinching mechanism, they become cinching cords, which
pass up through the trocar of the device. The device user pulls on
the exposed ends of the cinching cords located at the distal end of
the trocar to reduce the diameter of the ring core. When the device
user releases tension on the cinching cords, a cinching mechanism
(various embodiments detailed below and in FIGS. 6A-6E) prevents
the ring core from relaxing and the ring diameter from consequently
expanding, unless desired. Through a combination of extension of
the gunbarrel elements from the trocar and tension exerted on the
cinching cords, the device user can tailor the size of the ring
core.
[0057] While the preferred embodiment results in a ring that
adjusts symmetrically about its entire circumference, other
embodiments are possible and could be used to selectively reduce
certain segments of the ring more aggressively than others. For
example, a ring could be designed with stiffer coiled spacers among
the attachment blocks located on the anterior and posterior
segments of the ring, with more compliant coiled spacers among the
attachment blocks along the lateral sides of the ring. As this ring
is cinched closed, the distance between the attachment blocks along
the anterior and posterior segments would reduce more slowly than
the distance between adjacent attachment blocks along the sides of
the ring. The effect of this configuration would be a preferential
septal/lateral adjustment to the ring during opening and
closing.
[0058] In certain embodiments, each gunbarrel element is secured
into an anchoring block on the ring core. The gunbarrel elements
are pre-shaped to expand the ring outwards, once the gunbarrel
elements are pushed clear of the trocar. Each gunbarrel element
contains a gunbarrel pusher and a hollow insert, both of which are
activated by the device user via the control interface located
outside of the patient's body (detailed below and in FIGS. 8A-B).
Once the device user determines that the ring core is positioned
correctly upon the valve annulus, the device user activates each
gunbarrel pusher, which drives an attachment element into the
annular implant and the annular tissue.
[0059] The gunbarrel elements, attachment elements or the annular
implant may include touchdown sensors that detect contact with the
annulus, to confirm that there is contact between the implant and
the valve annulus at each point of attachment. The touchdown
sensors can incorporate any mechanism known in the art, such as
compressible buttons, resistance meters, or EKG sensors. In one
embodiment, the touchdown sensors communicate with the control
interface.
[0060] After each attachment element has been deployed, the annular
implant is securely attached to the valve annulus. A variety of
modalities for assessing mitral function, such as real time
transesophageal echo echocardiography, intravascular
echocardiography, and intracardiac echocardiography, may be used to
assess the physiologic effect of the implant on the mitral
function. Further adjustments of the device can alter the position,
size and shape of the annular implant. Once a desired result has
been achieved, the annular implant delivery device is
retracted.
[0061] One embodiment of the cinching mechanism, which locks the
ring core in place after adjustment, features a trap element which
sits inside a hollow cylindrical housing. A pushrod sits atop the
trap element. The cinching cords sit inside the trap element. At
rest, the trap element is closed with the cinching cords jammed
between the tapered feature located inside the trap element, thus
allowing no adjustment of the ring core diameter. However, if a
pushrod is engaged, the trap element is depressed, causing it to
flex open. As the trap element flexes open, the tapered feature
opens up, allowing the cinching cords to move freely. Releasing
pressure on the pushrod causes the trap element to re-close, again
cinching the cinching cords.
[0062] In various other embodiments of the cinching mechanism
according to the present invention, the adjustment means may
include a mechanism which may be threaded or non-threaded, and
which may be engaged by the action of a screw or worm screw, a
toothed mechanism, a ratchet mechanism, a rack and pinion
mechanism, a wedge-pin mechanism, a cam-like structure or such
other devices to permit discreet adjustment and retention of
desired circumference of the ring core, once the proper size is
determined.
[0063] In another embodiment, a device is provided for anchoring
and/or adjusting the annular implant. In this embodiment, a series
of retention barbs may be integrally formed with or fixedly
attached to the interior of the annular implant and are oriented to
facilitate placement, retention, and removal of the annular
implant.
[0064] The exemplary embodiment of this reversible attachment
apparatus employs unidirectional retention barbs. The retention
barbs are oriented in a consistent, tangential position with
respect to the annular implant. The retention barbs may be further
provided with a terminal hook, which allows for firm anchoring of
the annular implant into the surrounding valve annulus. The
retention barb/terminal hook apparatuses are movable between
extended and retracted positions. A movable retainer guide located
adjacent to the annular implant controls the action of the
retention barbs, such as via a worm gear. In the retracted
position, the retention barb/terminal hook apparatuses do not
engage the valve annulus. When the movable retainer guide is
engaged, the retention barb/terminal hook apparatuses extend
through the annular implant and into the valve annulus. The
terminal hooks act like anchors to fix the annular implant to the
valve annulus.
[0065] In another embodiment, a device is provided which acts as
the main controller of each annular implant delivery device
embodied in the present invention. The device, a control interface,
is located outside of the patient's body and incorporates a
plurality of attachment activator buttons, each of which drives a
single attachment element into the annular implant and valve
annulus by remotely controlling its movement.
[0066] The annular implant delivery device can be further
understood with reference to the exemplary, non-limiting
embodiments illustrated in FIGS. 1-8.
[0067] One embodiment of the annular implant delivery device is
shown in FIG. 1A-C. The embodiment shown is designed for delivery
of an annular implant to the mitral annulus of a heart. In other
embodiments, the delivery device is designed for any other annulus
within the human body that is creating dysfunction that might be
relieved by an implant capable of changing the size and shape of
that site and maintaining a desired size and shape after
surgery.
[0068] FIG. 2 shows a patient 50 in supine position preparing to
undergo a minimally invasive procedure for mitral valve repair
provided by one embodiment of the device of the present invention.
The right lateral aspect of the patient's chest 52 is exposed by
raising the right arm 54. The patient 50 has been sedated,
anesthetized and intubated for surgery. The right lung has been
deflated. An initial incision between the ribs is made for
insertion of an endoscopic camera for viewing of the pericardium.
Additional incisions are made for insertion of forceps and scissors
for the removal of a portion of the pericardium. A purse string
stitch is made in the left atrial wall, and an incision is made
into the atrial wall of the heart while tensioning the purse string
with a Ramel. The annular implant delivery device (not shown), is
then advanced through the atrial wall incision while sufficiently
loosening and then re-tightening the Ramel.
[0069] The annular implant delivery device 100 shown in FIGS. 1A-C
includes a trocar 110, a balloon expansion mechanism 112, a balloon
collar 126, gunbarrel elements 116, and anchoring blocks 118, as
well as an annular implant 120. The number of gunbarrel elements
116 and anchoring blocks 118 can vary. For simplicity, the delivery
device 100 is shown to include ten gunbarrel elements 116 anchored
into ten anchoring blocks 118. In preferred embodiments, the device
includes 2 to 12 or more gunbarrel elements 116 positioned in a
circular shape. The gunbarrel elements 116 may be configured to
other similar shapes such as oval, kidney bean or saddle-shaped,
depending on the desired shape of the recipient annulus. The
gunbarrel elements 116 may be a metallic, plastic, synthetic, or
any other biologically-compatible material, or combination thereof.
In one embodiment, the gunbarrel elements 116 are made of
titanium.
[0070] The more proximal portion of the gunbarrel elements 116 are
housed in the trocar 110. The alignment disc 142 located on the
interior of the trocar 110 provides separation to the gunbarrel
elements 116 so that they do not become twisted and entangled
during the device introduction. Each gunbarrel element 116 contains
a gunbarrel pusher (not shown) and a hollow insert (not shown),
both of which are activated by the device user via the control
interface located outside of the patient's body (detailed below and
in FIGS. 8A-B). The control interface provides a means of remotely
controlling the movement of each hollow insert and gunbarrel
pusher, which drives the attachment element into the annular
tissue.
[0071] The portion of the gunbarrel elements 116 adjacent to the
annular implant 120 can be constructed of or labeled with an
echo-opaque and/or a radio-opaque material for visualization of the
alignment against the implant and tissues. Alternatively, aspects
of the gunbarrel elements 116 can be constructed of thicker or
thinner material to contrast with the portions of the gunbarrel
elements adjacent to the annular implant 120. Such distinguishing
marking enables a surgeon to visualize the location of the
gunbarrel elements 116 and correspondingly, the annular implant
120, with respect to the recipient site during the delivery
procedure using TEE or other imaging modalities.
[0072] The shape and size of the annular implant 120 should be
chosen according to the anatomic needs of the intended recipient
site. Like the gunbarrel elements 116, the implant 120 may be round
or have other similar shapes such as oval, kidney bean or
saddle-shaped, depending on the desired shape of the recipient
annulus. Use of the terms "circumference" and "radius" and
modifications thereof does not denote that the referenced
structure, in most cases, the implant 120, is circular. For
non-circular shapes, such as a kidney bean, "circumference" is used
to mean the distance around the perimeter of the shape.
Particularly useful implants include those described in U.S. Pat.
No. 7,297,150 and U.S. Ser. No. 11/802,264 which are hereby
incorporated by reference in their entirety.
[0073] The composition of the annular implant 120 should also be
chosen according to the needs of the recipient site. The implant
120 can be accordion-like or it may have a smooth surface. In
various embodiments, the annular implant 120 may be a solid
structure, a tubular or otherwise hollow structure, or a structure
with an outer member and an inner member. In the latter embodiment,
the outer member of the implant body may serve as a covering for
the implant 120, and may be designed to facilitate and promote
tissue ingrowth and biologic integration to the annulus. The outer
member in such an embodiment may be fabricated of a biologically
compatible material, such as Dacron, PUT, malleable metals, other
biologically compatible materials, or a combination of such
biologically compatible materials in a molded, woven, or non-woven
configuration. The outer member in such an embodiment also serves
to house the inner member. Further, at least some portions of the
adjustable inner or outer member may be elastic to provide an
element of variable, artificial muscle tone to a valve, sphincter,
orifice or lumen in settings where such variability would be
functionally valuable, such as in the treatment of rectal
incontinence or vaginal prolapse.
[0074] During delivery of the annular implant, the annular implant
is secured to the delivery device. In one embodiment, the annular
implant is attached to a balloon collar and delivered to the valve
annulus via the balloon expansion mechanism (shown in detail FIGS.
3A-E). The annular implant can be formed from a deformable
material, and the balloon collar inflated within the valve annulus
to expand and deploy the annular implant. In embodiments such as
those described in FIGS. 3A-E, it will be appreciated that the
balloon collar may be progressively expanded via the balloon
expansion mechanism.
[0075] As shown in FIGS. 3A-E, the balloon expansion mechanism 112
of the annular implant delivery device 100 provides for the
inflation of the balloon collar 126 with either liquid or gas. The
balloon expansion mechanism 112 is composed of a hollow catheter
122 which feeds gas or liquid (such as saline) into the inflation
tube 124 to provide for expansion of the balloon collar 126. The
balloon collar 126 is deliberately hollow, or tubular, so that
blood may continue to flow through the annulus when the balloon 114
is inflated. A plurality of wheel-shaped trusses 128 extending from
the catheter 122 radially support the balloon 114.
[0076] In one embodiment (FIGS. 3D-E), a check valve 216 is
incorporated into the balloon expansion mechanism 112. The check
valve 216 would temporarily replace the functionality of an
anatomical valve, such as the mitral valve, during the time that
the balloon 114 is distended and the valve leaflets have been left
open and non-functional. The check valve 216 could be a
monoleaflet, bileaflet, or ball/cage design, similar to mitral
valve prosthetic devices known in the art.
[0077] As the balloon collar 126 inflates with gas or liquid (as
shown in FIG. 3C), it presses upon the mitral valve leaflets. The
leaflets are pushed away until they are flush against the side of
the heart. At this point, the outer surface of the balloon collar
126 is pushing against the mitral annulus. The annular implant 120
located around the balloon collar 126 is then secured to the
annulus, such as with the attachment means or anchoring barbs as
described below. Visual confirmation of the proper placement of the
annular implant 120 can be confirmed, such as with TEE.
[0078] In a preferred embodiment, the balloon collar 126 is
cylindrical or substantially cylindrical in shape. In other
embodiments, the balloon collar 126 may be of any size and shape
suitable for deployment in a lumen. The balloon 114 is preferably
made of a flexible biocompatible material. In one embodiment, the
balloon 114 is elastomeric, ranging from very soft to very rigid
stiffness. In a preferred embodiment, the balloon 114 is made from
an elastomeric material of medium stiffness. In another embodiment,
the balloon 114 has a predefined inflated shape and pressure.
Materials for the construction of balloons of the present invention
preferably include polyurethane, polyethylene terephthalate (PET),
polyethylene, polypropylene, polyesters and fluoropolymers.
[0079] FIGS. 4A-E depict a series of schematic views showing the
flexible annular implant 120 with gunbarrel elements 116. The ring
core 130 of the annular implant 120 is a flexible material made of
wire, braided wire or suture material. The ring core 130 runs
around the circumference of the device, then through a cinching
mechanism 132. As the ring core 130 passes through the cinching
mechanism 132, it becomes individual cords, hereafter referred to
as the cinching cords 138, which pass up through the trocar
110.
[0080] The device user pulls on the exposed ends of the cinching
cords 138 located at the distal end of the trocar 110 to control
the diameter of the ring core 130. Pulling on the cinching cords
138 reduces the size of the ring core 130. When the device user
releases tension on the cinching cords 138, a cinching mechanism
132 (various embodiments detailed below) prevents the ring core 130
from relaxing and the ring diameter from consequently growing.
Through a combination of extension of the gunbarrel elements 116
from the trocar 110 (described below) and tension exerted on the
cinching cords 138, the device user can tailor the size of the ring
core 130.
[0081] The ring core 130 is held in a circular shape by the
gunbarrel elements 116, which are pre-shaped to expand the ring
outwards, once the gunbarrel elements 116 are pushed clear through
of the trocar 110. The alignment disc 142 located on the interior
of the trocar 110 provides separation to the gunbarrel elements 116
so that they do not become twisted and entangled during the device
introduction. Each gunbarrel element 116 contains a gunbarrel
pusher (not shown) and a hollow insert (not shown), both of which
are activated by the device user via the control interface located
outside of the patient's body (detailed below and in FIGS. 8A-B).
The gunbarrel pusher drives the attachment element 144 into the
annular implant and the annular tissue.
[0082] Each gunbarrel element 116 is secured into an anchoring
block 118 on the ring core 130. Each anchoring block 118 anchors
its respective gunbarrel element 116 to a particular position on
the ring core 130. The anchoring blocks 118 are spaced by the
contiguous coiled spacers 136, which keeps the distance between
each pair of anchoring blocks 118 equidistant, or at any
pre-selected distance, as the ring core 130 diameter is manipulated
by the device user.
[0083] Each anchoring block 118 contains an opening through which
the ring core 130 passes, which secures the anchoring blocks 118 to
the ring core 130, thereby becoming a part of the annular implant
120. When the ring core 130 is positioned correctly upon the valve
annulus, the device user deploys the buttons on the control
interface to attach the annular implant 120 to the valve (detailed
below and in FIGS. 4A-B). Particularly useful gunbarrel and pusher
configurations can be seen in U.S. patent Ser. No. 12/026,624 which
is hereby incorporated by reference. Once deployed, the attachment
elements 144 penetrate the body of the anchoring blocks 118,
thereby securing the anchoring blocks 118 to the valve annulus. The
hollow inserts 140 of the gunbarrel elements 116 are angled outward
in order to prohibit the attachment elements 144 from connecting
into the valve leaflets or interfering with the balloon expansion
mechanism 112.
[0084] The surgeon may also confirm the position of the gunbarrel
elements 116 before advancing the attachment elements through the
valve annulus. The region of each gunbarrel element 116 distal to
the annular implant 120 can be labeled with an echo-opaque or
radio-opaque material, allowing the surgeon to view the location of
the gunbarrel elements 116 and annular implant 120 using TEE or
other imaging modalities.
[0085] Attachment elements 144 can have a multiplicity of forms.
The attachment elements 144 may be a metallic, plastic, synthetic,
or any other biologically-compatible material, or combination
thereof. In one embodiment, the attachment element 144 is made of a
shape memory alloy. In a preferred embodiment, the shape memory
alloy is nitinol. The configuration of the attachment element 144
can also vary. Examples of various embodiments of the attachment
element 144 are shown in FIGS. 5A-H. The attachment element 144 in
its relaxed position can be in the shape of a curve, as shown in
FIG. 5A; a loop, as shown in FIG. 5B; a coil, as shown in FIG. 5C;
a multi-coiled spiral, as shown in FIG. 5D; a two-coiled spiral, as
shown in FIG. 5E; a rod with a barb, as shown in FIG. 5F; a
bifurcated rod, as shown in FIG. 5G; or an anchor, as shown in FIG.
5H. The attachment element 144 can also be a pin or screw.
[0086] The gunbarrel elements, attachment elements or the annular
implant 120 may include touchdown sensors that detect contact with
the annulus, to confirm that there is contact between the implant
and the valve annulus at each point of attachment. The touchdown
sensors can incorporate any mechanism known in the art, such as
compressible buttons, resistance meters, or EKG sensors. In one
embodiment, the touchdown sensors communicate with the control
interface.
[0087] FIGS. 6A-E are a series of views showing various embodiments
of the cinching mechanism 132 (depicted in FIGS. 4A-C). The
cinching mechanism 132 locks the ring core 130 in place after
adjustment. The various embodiments of the cinching mechanism 132
(detailed below) are controlled at the control interface 196 via a
system of rods and wires, as appropriate. Controls consist of wires
to pull the ring core 130 material together, a control to
engage/release a lock for the cinching mechanism 132, and a tool
(not shown) that cuts the excess cinching wire at a point proximal
to the locking mechanism, allowing excess wire at a point proximal
to the locking mechanism, allowing excess wire to be removed.
[0088] One embodiment of the cinching mechanism 132 (shown in FIG.
6A) features a trap element 148 which sits inside a hollow
cylindrical housing 150. A pushrod 152 sits atop the trap element
148. An attachment tube 154 surrounds the pushrod 152. The cinching
cords 138 sit inside the trap element 148. At rest, the trap
element 148 is closed with the cinching cords 138 jammed between
the tapered feature 156 located inside the trap element 148.
However, if a pushrod 152 is engaged, the trap element 148 is
depressed, causing it to flex open. As the trap element 148 flexes
open, the tapered feature 156 opens up, allowing the cinching cords
138 to move freely, thereby allowing for adjustment of the flexible
ring core (130). Releasing pressure on the pushrod 152 causes the
trap element 148 to re-close, again cinching the cinching cords
138, thereby causing the diameter of the flexible ring core to
lock. After the ring size is positioned at its prescribed
dimension, the pushrod 152 is pulled upward causing the tines 158
located on the attachment tube 154 to flex inward, allowing the
pushrod-attachment tube assembly 152, 154 to pull free. The trap
element 148 and hollow cylindrical housing 150 remain attached to
the cinching cords 138 in order to keep the ring core 130 locked in
place.
[0089] Another embodiment of the cinching mechanism 132 involves a
ratchet-like mechanism. FIG. 6B depicts the ratchet-like structure,
whereby the ring core 130 passes through two collars 206 and wraps
around a spool 208. The interior of the spool 208 consists of a
gearwheel with teeth and a pawl that engages the teeth (not shown)
that adjusts the tension in the ring core 130. Like most
ratchet-like structures, the spool 208 can be rotated to tighten
the ring core 130 but prevents rotatable movement to loosen the
ring core 130, once it is tightened. The device user rotates the
spool 208 to tighten the ring core 130. The device user can
manually release the ratchet mechanism by lifting the pawl so that
it is clear of the teeth in order to rotate the spool 208 in either
direction (for loosening or tightening the ring core 130). In
another variation of this embodiment, a collar is securely attached
to the spool and can be adjusted to cinch the ring core in place
around the spool or allow it to freely turn in order to lock the
ring core in place or adjust the circumference of the ring
core.
[0090] Another embodiment of the cinching mechanism 132 involves a
wedge-pin cinching system (FIG. 6C-D). This embodiment features a
spring-loaded pushrod 160 that resides inside a collar 162 with a
cross-mounted pin 164. The cinching cords 138 pass through the
interior of the spring-loaded pushrod 160. The spring 166 of the
spring-loaded pushrod 160 pushes on the cross-mounted pin 164 so as
to jam and lock the cinching cords 138 in place. A half-washer 168
is attached to the cross-mounted pin 164. The half-washer cord is
attached to the half-washer 168. When the device user pulls on the
half-washer cord, the half-washer 168 releases the cross-mounted
pin 164, thereby releasing the jam on the cinching cords 138 and
effectively, unlocking them. When the half-washer cord (not shown)
is released by the device user, the cross-mounted pin 164 returns
to its jammed position and the ring is locked at the prescribed
dimension.
[0091] Another embodiment of the cinching mechanism 132 involves a
simple cam system.
[0092] FIG. 6E depicts a cinching mechanism formed by two movable
engagement structures in the form of opposing cams 170. In FIG. 2E
the cams 170 are rotated to their open or unlocked position,
whereby the cinching cords 138 move freely to adjust the
circumference of the ring core (not shown). The cams 170 can also
be rotated to their locked or engaging position wherein
longitudinal movement of the cinching cords 138 is prevented and
the ring core is locked into position.
[0093] FIGS. 7A-F illustrate another embodiment of the annular
implant 120 in accordance with the present invention. In this
embodiment, a reversible attachment apparatus 172 of the annular
implant 120 is detailed. A series of retention barbs 182 is
oriented to facilitate placement, retention, and removal of the
reversible attachment apparatus 172, whereby the reversible
attachment apparatus 172 may be used as an anchoring system for the
annular implant or as an annular adjustment system. In either
embodiment, the retention barbs 182 may be integrally formed with
or fixedly attached to the interior of the annular implant 120. The
retention barbs 182 can be composed of biocompatible material such
as nitinol, stainless steel, cobalt-based alloy or combinations
thereof.
[0094] As further shown in FIG. 7A, the exemplary embodiment of the
reversible attachment apparatus 172 of the annular implant 120
employs unidirectional retention barbs 182. The retention barbs 182
are oriented in a consistent, tangential position with respect to
the annular implant 120. The retention barbs 182 may be further
provided with a terminal hook 174 at the end, which allows for firm
anchoring of the annular implant 120 into the surrounding valve
annulus without permitting the annular implant 120 to rotate. The
terminal hooks 174, like barbed fish hooks, ensure the seating of
the annular implant 120 into the surrounding tissue.
[0095] The annular implant 120 contains an upper compartment 176
and a lower compartment 178, which houses the retention barbs 182
and terminal hooks 174. The compartments are divided by a movable
retainer guide 180, which controls the action of the retention
barbs 182 via a worm gear (described below). The upper compartment
176 may be composed of the ring core. The lower compartment 178 may
be composed of foam or a foam-like material such as polyurethane
foam, XPS foam, Styrofoam or some other manufactured foam encasing
the retention barbs 182 until deployed. The exterior of the annular
implant 120 (housing the upper and lower compartments) in such an
embodiment may be fabricated of a biologically compatible material,
such as Dacron, PTFE, malleable metals, other biologically
compatible materials, or a combination of such biologically
compatible materials in a molded, woven, or non-woven
configuration.
[0096] FIG. 7B depicts one retention barb/terminal hook apparatus
182, 174 housed inside the lower compartment 178 of the annular
implant 120. The retention barb housing 184 is a cleft on the inner
surface of the lower compartment 178 of the annular implant 120
which prevents the retention barb 182 from engaging the valve
annulus 188 prior to deployment. Additionally, the retention barb
housing 184 serves as a guide for the terminal hook 174 upon
deployment into the valve annulus 188. The terminal hook limiter
186 keeps the terminal hook 174 positioned for proper
deployment.
[0097] FIGS. 7C and 7D illustrate an embodiment of the reversible
attachment apparatus 172 of the annular implant 120 in which the
lower compartment 178 includes retention barbs 182 and retention
barb/terminal hook apparatuses 182, 174, which are movable between
extended and retracted positions. In the retracted position shown
in FIG. 7C, the retention barbs 182 and the retention barb/terminal
hook apparatuses 182, 174 do not engage the valve annulus. When the
movable retainer guide 180 is pulled in the direction of the arrow
in FIG. 7C, the retention barbs 182 and retention barb/terminal
hook apparatuses 182, 174 extend through the lower compartment 178
and into the valve annulus 188, as depicted in FIG. 7D. The
terminal hooks 174 act like anchors to fix the annular implant 120
to the valve annulus 188.
[0098] FIGS. 7E-G illustrate the variable modes of the reversible
attachment apparatus of the annular implant. FIG. 7E depicts the
compressed mode, whereby the device is in position to be inserted
into the canula trochar or catheter. FIG. 7F depicts post-insertion
deployed mode, whereby the annular implant 120 rests passively on
top of the valve annulus 188 with the lower compartment 178
expanded. FIG. 7G depicts the activated mode, whereby the annular
implant 120 is attached to the valve annulus 188 via the retention
barb/terminal hook apparatuses 182, 174.
[0099] The drive mechanism 192, depicted in FIGS. 7E-G, contains
and supports a mechanical worm gear with an attached first gear
head 210 which mates with a second gear head 212. The second geared
head 212 is attached to an adjustment stem 214 which is machined to
receive a screwdriver-like adjustment element. The various
embodiments according to the present invention may require a number
of forms of adjustment elements. In the present example, the
adjustment element is provided as a finely coiled wire with a
distal tip machined to be received by a receiving slot (not shown)
in the adjustment stem 214. The relationship between the distal tip
of the adjustment element and the adjustment stem 214 is
mechanically similar to a screwdriver bit and screwhead, such that
torsion imparted to the adjustment means by the device user will
result in turning the adjustment stem 214 and a second geared head
212. This turning of the adjustment stem 214 and the second geared
head 212 allows motion of the first geared head 210 and worm, which
creates motion of the movable retainer guide 180 as the worm
engages with a series of adjustment stops. The adjustment stops may
be slots, holes, detents, dimples, ridges, raised elements, or
other mechanical features.
[0100] FIGS. 8A-D depict the control interface 196, which acts as
the main controller of the annular implant delivery device. The
control interface 196 incorporates a plurality of attachment
activator buttons 198, each of which drives a single attachment
element (not shown) into the annular implant and valve annulus by
remotely controlling the movement of the each gunbarrel pusher.
Attachment of a two-button activation device 200 to an individual
attachment activator button 198 allows the device user to control
the delivery of the hollow insert (not shown) and the attachment
element (not shown). When the device user pushes the hollow insert
button 202 of the two-button activation device 200, the hollow
insert (not shown) is driven through the annular implant and into
the annular tissue. When the device user pushes the gunbarrel
pusher button 204 of the two-button activation device 200, the
gunbarrel pusher (not shown) is activated, thereby driving the
attachment element (not shown) into the annular implant and valve
annulus. If both the attachment activator button 198 and the
gunbarrel pusher button 204 of the two-button activation device 200
are pushed simultaneously, the hollow insert (not shown) and the
gunbarrel element (not shown) are driven into the annular implant
and valve annulus.
[0101] In a preferred embodiment, deployment of the hollow insert
and attachment element is as follows: first the user depresses the
two-button activation device 200 that simultaneously advances the
hollow insert and the gunbarrel pusher (not shown). The tip of the
hollow insert penetrates into the annulus tissue. This penetration
depth may be controlled by placing a mechanical stop in the
pushbutton system to limit the depth of penetration of the hollow
insert. Second, the user depresses a button to advance the
gunbarrel pusher. As the gunbarrel pusher is advanced, it pushes
the attachment element out of the distal tip of the hollow insert
and into annular tissue. This penetration depth may also be
controlled by a mechanical stop and is roughly equal to half of the
length of the attachment element. Third, the user withdraws the
hollow insert while holding the gunbarrel pusher in contact with
the proximal end of the attachment element. This action strips the
attachment element out of the hollow insert while keeping the
attachment element at its intended penetrated depth of the annulus.
Fourth, as the retreating hollow insert releases the proximal end
of the attachment element, the attachment element springs to its
curved shape, capturing the anchoring block and holding it against
the annulus.
[0102] Once the annular implant is successfully attached to the
valve annulus via any one of the aforementioned embodiments, the
annular implant delivery device is removed from the patient's body
and the Ramel or purse-string tourniquet is further tightened and
tied off. The chest incision can then be closed. In various
embodiments, the annular implant delivery device may be configured
to allow re-introduction for adjustment of the annular implant.
Furthermore, alternate methods for use of an adjustable implant may
provide for periodic, post-implantation adjustment of the size of
the implant to fit the valve annulus as needed to accommodate
growth of the site in a juvenile patient or other physiologic
changes and needs of the patient.
[0103] The present invention and the methods for its use anticipate
many alternate embodiments in other potential applications in the
broad fields of medicine and surgery. Among the other potential
applications anticipated according to the present invention are
adjustable implants for use in the treatment of morbid obesity,
urinary incontinence, anastomotic strictures, arterial stenosis,
cervical incompetence, ductal strictures, and anal incontinence.
The preceding discussions are intended to be exemplary embodiments
according to the present invention and should not be construed to
limit the present invention and the methods for its use in any way.
Other features and embodiments of the present invention will be
apparent to those in the art in view of the present disclosure.
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